You may need further testing or a biopsy to look for other causes of mouth ulcers. Canker sores are not cancer and do not cause cancer. There are types of cancer, however, that may first appear as a mouth ulcer that does not heal.

Apply a mixture of half hydrogen peroxide and half water directly to the sore using a cotton swab. Follow by dabbing a small amount of Milk of Magnesia on the canker afterward. Repeat these steps 3-4 times a day.

Rinse your mouth with a mixture of half Milk of Magnesia and half Benadryl liquid allergy medicine. Swish mixture in the mouth for about 1 minute, then spit out.

Medicines prescribed by your health care provider may be needed for severe cases. These may include:

Chlorhexidine mouthwash

Stronger medicines called corticosteroids that are placed on the sore or take in pill form